Some systems rely on engines to drive generators for producing electrical power for the system. These systems may vary the electrical power output of an electrical machine (e.g., alternator, generator, or other electrical power producing machine) by controlling the engine or engines that are driving the electrical power producing machine, at different speeds. Mechanical components and operational characteristics of an engine may degrade over time. Eventually a system may need to be taken offline so an engine that has degraded can be overhauled or even replaced. As each engine is unique and degrades at a different rate, the individual engines in a multi-engine power system may reach their respective service time or end-of-life at different times. To avoid having to take a multi-engine system offline each time a particular engine reaches its respective service time or end-of-life, all of the engines of the multi-engine system may be replaced when one engine needs replacing, even though the other engines may still possess at least some useful life.